Automotive fuel pump with modular pump housing

Abstract

A modular automotive fuel pump includes lower and upper housings, a motor, a rotary pumping element, and a combination clearance land and flow guide which determines the axial clearance between the pump impeller and the pump housing.

We claim: 
     
       1. A modular automotive fuel pump, comprising: a lower housing having a first end with a central, annular, planar sealing surface, an outer mounting annulus which is coplanar with the central sealing surface, and a second end with a fuel inlet;   an upper housing having a first end with a central, annular, planar sealing surface, an outer mounting annulus which is coplanar with the central sealing surface, and second end with a fuel outlet;   a motor having a shaft extending therefrom;   a rotary pumping element, mounted on said motor shaft between said lower and upper housings, comprising a bladed, two-sided disk having a circular, planar sealing surface extending radially outwardly from the center on each side of said disk, with said circular sealing surfaces of the rotary pumping element being parallel to each other and parallel to said annular sealing surfaces of the lower and upper housings; and   a combination clearance land and flow guide comprising an annular ring positioned between said lower and upper housings and having a separate annular face in contact with the mounting annulus on the first end of each housing, so as to establish axial clearance spaces between the sealing surfaces of the disk and the corresponding sealing surfaces of the lower and upper housings, with said combination land and guide having a radially inward surface defining a circumferential wall about said pumping element, and with the axial thickness of said combination land and guide being only slightly greater than the axial thickness of said disk, such that the sealing surfaces of the disk and the corresponding sealing surfaces of the lower and upper housings will cooperate to control the flow of fuel through the axial clearance spaces.   
     
     
       2. A pump according to claim 1, wherein said rotary pumping element comprises a regenerative turbine impeller. 
     
     
       3. A pump according to claim 1, wherein each clearance space extending between a sealing surface of the disk and a sealing surface of the pump housing comprises a truncated cylindrical space. 
     
     
       4. A pump according to claim 1, wherein the sealing surface and mounting annulus of said lower housing are generally defined by an annular channel chamber extending from said fuel inlet to a location about 315 degrees of rotation from the inlet. 
     
     
       5. A pump according to claim 1, wherein the sealing surface and mounting annulus of said upper housing are generally defined by an annular channel chamber extending from said fuel outlet to a location about 315 degrees of rotation from the outlet. 
     
     
       6. A pump according to claim 1, wherein said sealing surfaces have a lapped finish. 
     
     
       7. A method for manufacturing a modular automotive fuel pump characterized by a motor driven impeller housed between lower and upper pump housings and having sealing surfaces cooperating with associated sealing surfaces on said housings, comprising the steps of: fabricating the lower and upper pump housings, with each housing comprising a first axially outward end and a second, axially inward end, with said second ends being generally planar and having annular sealing surfaces adapted to seal with said impeller;   fabricating a population of combination clearance land and flow guide components, with each component comprising a generally annular ring adapted for positioning between the lower and upper housings and having a separate annular face for contacting the second end of each lower and upper housing;   fabricating a population of impeller components, with each comprising a bladed, two-sided disk having a circular, planar sealing surface extending radially outwardly from the center on each side of said disk, both sealing surfaces being parallel to the other;   building an insert module by selecting a combination land and guide component and an impeller component from each component's respective population such that the axial length of the combination land and guide component exceeds the axial length of the impeller component by an amount sufficient to establish a desired operating clearance between the impeller and the second ends of the lower and upper pump housings; and   assembling said insert module between said lower and upper housings, with said circular sealing surfaces of the impeller being parallel to said annular sealing surfaces of the lower and upper housings.